Keying device for pulleys.



No. 786,039. PATENTED MAR. 28, 1905.

. D. G. LANGLANDS.

KEYING DEVICE FOR PULLEYS.

' split pulley, in connection with a common form UNITED STATES PatentedMarch 28, 1905.

PATENT OEEIcE.

DANIEL G. LANGLANDS, OF WINTHROP, MASSACHUSETTS, ASSIGNOR TO JAMES H.ROBERTS & COMPANY, OF BOSTON, MASSACHUSETTS.

KEYING DEVICE FOR PULLEYS.

SPECIFICATION forming part of Letters Patent No. 786,039, dated March28, 1905 Application filed October 8, 1904:. Serial No. 227,640.

a citizen of the United States, and a resident of Winthrop, in thecounty of Suifolk and State of Massachusetts, have invented a new anduseful Improvement in Keying Devices for Pulleys, of which the followingis a full, clear, and exact description, reference being had to theaccompanying drawings, forming a part of this specification, inexplaining its nature.

My invention relates to a keying device for such classes of pulleys ashave clamp members for securing the pulley to a shaft.

The device is especially applicable to the of which it is illustrated inthe drawings.

Referring therefore to the drawings, in connection with which the devicecan best be seen and understood, Figure 1 shows the pulley and improvedlocking device partly in side elevation and partly in cross-section.Fig. 2 shows the plate and key of the locking device in verticallongitudinal section. Fig. 3 shows a cross-section of the same, and Fig.4 shows the two parts in perspective.

In the drawings, A represents a split pulley. The face of the pulleycomprises the two segmental halves a (0, having the cross-ties or clampmembers a a tied together by the draft- ;bolts (0*, by which means thetwo halves of the pulley are united and the pulley formed. .the centerof the members a a when in conjunction is formed the bore a of thepulley. Through this bore a there extends a shaft A. .The bore of thepulley is made somewhat larger than the shaft extending through it,

and inserted between the clamp members and the shaft is a bushingcomprising the sections B B. It is mechanically evident with a pulleythus made that after the two halves of the pulley and sectional bushinghave been applied to the shaft then upon tightening the draft-bolts athe clamp members will be drawn together, thereby combining the segmentsforming the face of the pulley, while the clamp members coming togetherwill draw against the sectional bushing and make the same hug againstthe, shaft A, by which means means for locking the pulley upon the shaftit is noted that the bushing is cut away in part or a section thereofremoved, leaving an opening or keyway when the parts are in proper placein the bore of the pulley between the shaft and one of the adjacentclamp members. Into this opening, before the two halves of the pulleyhave been tightly clamped together, is inserted a key C to bear againstthe shaft, while between the key and the wall of the adjacent clampmember, bearing against the same and facing the shaft, is inserted a camor plate O. The key C, it is to be noted, is a bar of metal formed onits side with gripping edges 0 c, which engage with the shaft, while theback edge 0 of the key is made rounding and is adapted to engage withthe inside surface of the cam or plate O, made concave. With respect tothe inside concave surface 0 of the plate the concavity is such thatwhen the plate is thus in place between the key and the wall of theclamp member'bearing against the same a gradually-lessening radialdistance will separate the inside surface of the plate toward eitherside than at the center thereof, against which the rounding back of thekey has its normal bearing, by which means cam-surfaces are formed, withthe effect that upon the key turning, which is occasioned by the pulleyslipping upon the shaft or the shaft turning independently of thepulley, the rounding back of the key will be moved to bear against oneor the other of these cam-surfaces, depending upon the direction thepulley is displaced, resulting. in the key becoming wedged in by itsbearing against the cam-surface, which so binds the key that itsgripping edges will bite more firmly into the shaft, thereby preventinga further displacement of the pulley and holding it locked and secure inplace. It is also to be noted that the concavity of the plate or thecurve of the cam-surfaces is such that the more the pulley tends tobecome displaced the tighter will the key be wedged upon the shaft.

With reference to the cam or plate (1 in further detail it is to beobserved that the outside surface 0" of the plate which bears againstthe wall of the clamp member is provided with projections c which areadapted to press into the clamp member for holding the plate, so that itwill not slip or become displaced. In width the plate substantiallyfills the gap made by the cut in the bushing, still not so as to preventthe bushing from being tightened upon the shaft when the two halves ofthe pulley are clamped together. Itis also to be noted that the plate isprovided with end flanges 0 0 so dependent as to prevent an end motionof the key after its insertion, and this especially should the pulley atany time be loose upon the shaft.

The operation of the locking device is as follows: Assuming the twohalves of the pulley and sectional bushing to be applied to the shaftand the key and plate inserted into the hole or opening formed in thebushing, with the gripping edges of the key contacting with the shaftand the rounding back edge thereof bearing against the plate at aboutthe center of its inside concave surface, then upon the coming togetherof the clamp members by the tightening of the draft-bolts (0 thesections of the bushing will not only be made to tighten upon the shaft,as before explained, but as the clamp members come together pressurewill also be brought to bear against the plate and key of the lockingdevice. The projections 0 upon the upper surface of the plate will firstbe pressed into the adjacent wall of the clamp member, then upon afurther tightening of the bolts the pressure of the clamp member uponthe plate will bind the interposed key tight against the shaft, so thatits gripping edges will bite into or engage with it. The key thusengaging with the shaft will not slip, but remain fixed to it, with theeffect that if the pulley slips upon the shaft or the shaft turnindependently of the pulley in either case the rounding edge of the keywill begin to bear against one or the other of the camsurfaces of theplate, depending upon the direction of displacement of the pulley, andby reason of such bearing the key, as before explained, will becomewedged more tightly upon the shaft, preventing any further displacementof the pulley and holding it locked secure in place.

The locking device is extremelysimple; also, its making andconstruction. The shaft and portions surrounding the bore of the pulleyare left intact. The device operates to lock or key the pulley upon theshaft by tightening the same bolts and clamp members which secure thepulley thereto. By its use the pulley may be fastened to the shaft atany point and its position changed or the pulley removed simply byloosening or unscrewing the pulleybolts. Another important advantageresides in the fact that the same relation between pulley and shaft ismaintained all along the bore of the pulley, for the key extendsentirely through it, so that however tight the pulley may be locked uponthe shaft it will still fit evenly, and accordingly will run true.

Having thus fully described my invention, 1 claim and desire to secureby Letters Patent of the United States-- 1 In a keying device forpulleys, the combination with a shaft and a pulley loosely fittingthereon of a cam inside said pulley facing said shaft and movable withsaid pulley, and a key between said cam and shaft, one edge of which keyis adapted to engage said shaft and the other edge thereof to engagewith the inside surface of said cam upon said pulley or shaft turningindependently of one another.

2. In a keying device for pulleys, the combination with a shaft and apulley loosely litting thereon of a sectional bushing inside the bore ofsaid pulley, said bushing being cut away in part leaving a keyway oropening through the bore of the pulley alongside the shaft, a cam insidesaid pulley, occupying a portion of the opening therein and facing saidshaft, and a key between said cam and shaft, one edge of said hey beingadapted to engage said shaft and the other edge thereof to engage withthe inside surface of said cam upon said pulley or shaft turningindependently of one another.

3. In a keying device for pulleys, the combination with a pulley and ashaft, said pulley having clamp members for securing it to the shaft, ofa sectional bushing interposed between said clamp members and saidshaft, said bushing being cut away in part leaving an opening throughthe bore of the pulley and between one of its clamp members and theshaft, a key inside said opening, said key being adapted to engage withthe shaft, a plate likewise within said opening interposed between theback edge of said key and the adjacent wall of the clamp member, saidplate being adapted on the outside to bear against said portion of thewall of the clamp member and on the inside concaved to form acam-surface against which the back edge of the key may have bearing,substantially as described.

4:. In a keying device for pulleys, the combination with a pulley and ashaft, said pulley having clamp members for securing it to the shaft, ofa sectional bushing interposed between said clamp members and saidshaft, said bushing being cut away in part leaving an opening throughthe bore of the pulley and between one of its clamp members and theshaft, a key inside said opening, said key being provided with grippingedges, which engage with the shaft and having a rounding back edge, aplate likewise within said opening interposed between the rounding backedge of said key and the adjacent wall of the clamp member, said plateon the outside being adapted to bear against said portion of the wall ofthe clamp member without slipping and on the inside made concaved toform opposite cam-surfaces against either one of which the rounding backedge of the key may have bearing, substantially as described.

5. In a keying device for pulleys, the combination with a pulley and ashaft, said pulley having clamp members for securing it to the shaft, ofa sectional bushing interposed between said clamp members and saidshaft, said bushing being cut awayin part leaving an opening through thebore of the pulley and between one of its clamp members and the shaft,and a key inside said opening, said key being provided with grippingedges on its one side which engage with the shaft and having a roundingback edge, a plate likewise within said opening interposed between therounding back edge of said key and the adjacent wall of the clampmember, said plate on the outside being adapted to bear against saidportion of the wall of the clamp member and provided with projectionswhich engage with the same, which plate on the ends is formedwithdepending flanges preventing lateral displacement of said key and onthe inside made concave to form opposite cam-surfaces against either oneof which the rounding back edge of the key may have bearing,substantially as described.

6. In a keying device for pulleys, the combination with a shaft and apulley loosely fitting thereon, of cam and key members inside saidpulley and between it and said shaft, one of which members is adapted toengage with said pulley and the other with said shaft and which are socoordinated that said key member will engage with the cam-surface ofsaid cam when said pulley and shaft turn inclependently of one another,substantially as and for the purposes set forth.

7. In a keying device for pulleys, the combination with a shaft and apulley loosely fitting thereon, of a sectional bushing inside the boreof said pulley, said bushing being cut away in part leaving a keyway oropening through the bore of the pulley alongside the shaft, cam and keymembers inside said pulley, occupying a portion of the opening therein,one of which members is adapted to engage with said pulley and the otherwith said shaft, and which are so coordinated that said key member willengage with the cam-surface of said cam when said pulley and shaft turnindependently of one another.

DANIEL G. LANGLANDS.

In presence of M. V. FOLEY, JOHN E. R. HAYES.

